Where 'Things Go The Other Way': The Stereochemistry of Lewis Carroll's Looking-Glass World

Abstract

In the opening scene of Through the Looking-Glass, Alice asks a feline friend, 'How would you like to live in Looking-Glass House, Kitty? I wonder if they'd give you milk in there? Perhaps Looking-Glass milk isn't good to drink?' Alice's speculation regarding the potability of Looking-Glass milk has long been considered by chemists to be Carroll's subtle reference to stereoisomers. Discovered by Louis Pasteur in 1848, stereoisomers are molecules that contain the same number and kinds of atoms but differ from each other in spatial orientation. The stereoisomers of lactose (C12H22O11) in milk exist as nonsuperimposable mirror images of each other; therefore, the milk Alice would drink in the Looking-Glass House is of the opposite three-dimensional configuration than the milk of the 'regular' world, and for that reason, Carroll wonders if the former might produce an insalubrious, rather than healthful, effect. While much has been written about this particular representation of stereoisomerism in Through the Looking-Glass, scientists and literary scholars alike have failed to recognize the potential chemical subtext of the story's other mirror images. In this paper, I will argue that manifestations of stereoisomerism are not just confined to the looking-glass milk scene, and that the ways in which Carroll explores issues of doubling, inversion, and reversibility in the 'mirror world' suggest a far more elaborate contemplation of the implications of stereoisomers. Characters such as Tweedledum and Tweedledee and Humpty Dumpty, the notion of 'unbirthdays', and even to some extent Carroll's pseudonymity reflect the author's fascination with, and at times anxiety about, the idea of a dual chemical existence, a world in which every person, place, and thing comprises two like yet non-superimposable forms.